1. Field of the Invention
The present invention relates to an automatic sewing apparatus adapted for use in the sewing of a trim cover assembly of automotive seat, and is in particular directed to the one which permits sewing together of two different blank cover materials each having different shapes of edges (for example, curved, sinuously-cut or rectilinear edges); namely, sewing the juxtaposed different edges of those two cover materials into a trim cover assembly of automotive seat.
2. Description of the Prior Art
Producing a trim cover assembly for use on an automotive seat, as well known, involves the steps where operators cut out various shapes of blank cover materials to provide a number of seat cover constituent parts; for instance, a central seating part, a peripheral bolster part and a side wall part, which form the trim cover assembly, and then sew those parts together into a three-dimensional shape of trim cover assembly, which is subsequently to be affixed over a cushion member for the seat assembling purpose.
By and large, those three separate cover elements have their own edges whose shapes are different from one another. In some cases, the edge of the central seating part is formed rectilinearly while that of the adjoining peripheral bolster part is formed in a curved or uneven manner, and in other cases, both central seating and peripheral bolster parts are formed in an uneven manner differently from each other. Consequently, in assembling the trim cover assembly, the different edges of the cover elements are juxtaposed together precisely and put in a state for sewing by a sewing machine.
Such step of setting the cover elements for sewing and subsequent sewing operation has been executed manually by operators, such that the operators feed the unevenly shaped edge of the peripheral bolster part along the differently shaped edge of the central seating part, towards the sewing machine, in order to sew them together.
At the side of the operators, therefore, an extreme attention and high degree of skill are required for moving and feeding the cover elements for a precise sewing thereof, and no effective automatic system exists in that respect. As a result, sewing the uneven ledges of seat cover elements has remained a difficult manual technique that stalemates the improvement in rapidity of sewing as well as innovation in this particular field.